Dielectric plating/coating of aluminum and/or copper with "decent" tribological/wear properties

I am a supplier for electronic test devices. I need to conformally coat a conductive or semi-conductive workpiece (a plate of ~1 mm thickness with tens to hundreds of thru holes of roughly 1 mm diameter). The material will be copper, aluminum, or possibly silicon. I need a coating that will be "mildly" electrically insulative (breakdown of ~1000 V/m with resistivity of 1e-7 Ohm-m) but have "decent" wear/tribology properties. I realize "decent" is a weak description, but I could best describe it as something like a spring in a click-pen--it will see some interaction with neighboring elements, but not "too much", just need to keep the workpiece electrically isolated from this level of mechanical interaction. I have looked at atomic layer deposition and PVD of ZrN and diamond-like carbon...the catch is that I am trying to plate thru-holes and the PVD processes don't seem to give me the conformality that I need. I need coating thickness on the order of 10 microns ± 3 microns. I also am most concerned with the electrically insulative properties on the barrel of the holes, not so much of the surfaces "perpendicular" to the holes if that makes sense.